JP6163495B2 - Apparatus and method for actuating a valve - Google Patents

Description

  Embodiments of the invention disclosed herein generally relate to an apparatus and method that has an actuator valve and is configured to carry hydrostatic pressure in a reciprocating compressor used in the oil and gas industry.

  A compressor is a mechanical device that increases the pressure of a gas and is found in engines, turbines, power generation, cryogenic applications, oil and gas refining, and the like. Due to its wide range of applications, various mechanisms and techniques related to compressors are often the subject of research aimed at improving compressor efficiency and solving problems related to specific operating environments. One special situation that must be considered with respect to compressors used in the oil and gas industry is that the fluid being compressed is often corrosive and flammable. The American Petroleum Institute (API), the body that establishes industry standards for the equipment used in the oil and gas industry, has issued API 618, a document that lists the minimum set of requirements for reciprocating compressors ( The version as of June 2011 is incorporated herein by reference).

  Compressors are classified as positive displacement compressors (eg, reciprocating, screw or vane compressors) or dynamic compressors (eg, centrifugal or axial compressors). In a positive displacement compressor, the gas is compressed by trapping a certain amount of gas and then reducing its volume. In a dynamic compressor, the gas is compressed by transferring kinetic energy from a rotating element (such as an impeller) to the gas compressed by the compressor.

  FIG. 1 is a diagram of a conventional two-chamber reciprocating compressor 10 (ie, a positive displacement compressor) used in the oil and gas industry. Compression takes place in the cylinder 20. The fluid to be compressed (eg natural gas) is introduced into the cylinder 20 via the inlet 30 and is discharged via the outlet 40 after compression. The compressor operates in a circulation process, and the fluid is compressed by moving the piston 50 between the head side 26 and the crank side 28 in the cylinder 20 during the circulation process. The piston 50 divides the cylinder 20 into two compression chambers 22 and 24 that operate at different stages of the circulation process, and when the volume of the compression chamber 22 is at its minimum value, the volume of the compression chamber 24 is at its maximum value and vice versa. It is the same.

Suction valves 32 and 34, when opened, allow fluid to be compressed (ie, having a first / suction pressure p ₁ ) from inlet 30 into compression chambers 22 and 24, respectively. When the discharge valves 42 and 44 are opened, compressed fluid (ie, having a second / discharge pressure p ₂ ) can be discharged from the compression chambers 22 and 24 via the outlet 40, respectively. The piston 50 moves by energy transmitted from the crankshaft 60 via the crosshead 70 and the piston rod 80. Conventionally, a suction and compression valve used in a reciprocating compressor has a valve closed state (that is, prevents passage of fluid) and a valve open state (that allows passage of fluid) due to a differential pressure across the valve. It is an automatic valve that can be switched between.

A typical compression cycle includes four stages: expansion, suction, compression, and discharge. When the compressed fluid is discharged from the compression chamber at the end of the compression cycle, a small amount of fluid at delivery pressure p ₂ remains confined within the clearance volume (ie, the minimum volume of the compression chamber). In the expansion phase and suction phase of the compression cycle, the piston moves to increase the volume of the compression chamber. The delivery valve closes at the beginning of the expansion phase (the suction valve remains closed), thus increasing the volume of the compression chamber where fluid is available, thus reducing the pressure of the trapped fluid. The suction phase of the compression cycle begins when the pressure in the compression chamber becomes equal to the suction pressure p ₁ and the suction valve opens. In the suction stage, the volume of the compression chamber and the amount of fluid to be compressed (pressure p ₁ ) increase until the maximum volume of the compression chamber is reached.

During the compression and discharge phase of the compression cycle, the piston moves in a direction opposite to the direction of movement during the expansion and compression phase, reducing the volume of the compression chamber. During the compression phase, both the suction and delivery valves are closed and the volume of the compression chamber decreases, so the pressure of the fluid in the compression chamber increases (from suction pressure p ₁ to delivery pressure p ₂ ). The delivery phase of the compression cycle begins when the pressure in the compression chamber is equal to the delivery pressure p ₂ and the delivery valve opens. In the delivery phase, fluid at delivery pressure p ₂ is discharged from the compression chamber until the minimum (clearance) volume of the compression chamber is reached.

  By using an actuator type valve instead of an automatic valve (which opens and closes by a differential pressure across the valve), the efficiency can be increased and the clearance volume can be reduced. However, due to the special technical requirements of reciprocating compressors used in the oil and gas industry, i.e. the high force, large displacement and short response time compared to those achieved by currently available actuators. The use of actuator valves has not yet progressed. Some currently available actuators meet one of these requirements, but not all of these conditions can be met simultaneously. In addition, the corrosive and damaging explosion risks associated with the use of reciprocating compressors in the oil and gas industry further hinder the use of actuator-type valves, necessitating the placement of actuators outside the compressor. ing.

  Since the actuator is located outside the reciprocating compressor, the large force required for the actuator to operate the valve closing member is partly the differential pressure between the fluid in the reciprocating compressor and the environment (known as hydrostatic pressure). Caused by). In addition, when an electromagnetic actuator generates a large force in a short operating time, the actuator can also generate a significant amount of heat, and this heat dissipation can be a problem (sometimes even requiring a cooling system). is there). For this reason, it is advantageous if the force required to actuate the valve can be reduced. Accordingly, it is desirable to have a valve assembly and method that can reduce the force required to operate a valve in a reciprocating compressor.

International Publication No. 2009-146222

  Various embodiments of the present inventive concept present an apparatus and method that solves the technical problem of operating a reciprocating compressor valve used in the oil and gas industry. In particular, the various embodiments are configured to eliminate the effect of hydrostatic pressure in the compressor and thus reduce the required actuation force. By reducing the operating force, an electromagnetic actuator that can generate the necessary (smaller) force in the short operating time required for reciprocating compressors used in the oil and gas industry, without causing heat dissipation problems It becomes possible to use it.

  According to one illustrative embodiment, a valve assembly that can be used in a reciprocating compressor for the oil and gas industry includes an actuator, a shaft, a collar, and a thrust bushing. The actuator is configured to cause displacement. The shaft is configured to undergo rotational motion caused by this displacement and to enter the interior of the compressor body of the reciprocating compressor. The collar is arranged close to the position where the shaft enters the inside of the compressor body. The thrust bushing is disposed between the collar and the compressor body. The rotational movement actuates the valve closing member of the valve inside the compressor body.

  According to yet another exemplary embodiment, a method of operating a valve inside a reciprocating compressor used in the oil and gas industry includes the steps of causing displacement and rotational movement due to displacement by a first fluid medium. A second flow medium having a pressure substantially higher than the first flow medium from the outside of the compressor to the inside of the compressor body via the shaft. In addition, the method uses a collar on the inner shaft of the compressor body and a thrust bush between the collar and the compressor body to provide a hydrostatic pressure between the second medium and the first medium. A step of removing the force caused by.

  According to yet another exemplary embodiment, a reciprocating compressor used in the oil and gas industry includes (1) a compressor body configured to separate fluid from the environment, and (2) on the compressor body. And a valve assembly configured to operate the valve. The valve assembly is (A) an actuator that is disposed outside the compressor body and causes displacement, and (B) is subjected to rotational motion caused by the displacement and enters inside the compressor body of the reciprocating compressor. To reduce the force caused by hydrostatic pressure between the fluid and the environment, and (C) the collar disposed close to the position where the shaft enters the inside of the compressor body. And a configured thrust bushing. The rotational movement actuates the valve closing member of the valve.

  According to yet another exemplary embodiment, a method is provided for retrofitting a reciprocating compressor that initially has an automatic valve. The method includes a step of attaching an actuator configured to cause displacement outside a compressor body of a reciprocating compressor, and a shaft entering the inside of the compressor body. Connecting a shaft having a collar to the valve closing member of the automatic valve proximate to a position that enters the inside of the compressor body. The method further includes compressing a thrust bushing configured to damp a hydrostatic pressure force between the fluid inside the compressor body and the environment outside the compressor body inside the compressor body. Including the step of mounting between the machine body.

  The accompanying drawings, which are incorporated in and constitute a part of this specification, are illustrations of one or more embodiments, and together with the detailed description, describe these embodiments.

1 is a schematic view of a conventional two-chamber reciprocating compressor. 1 is a schematic diagram illustrating a valve assembly having an actuator inside a compressor body. 1 is a schematic diagram illustrating a valve assembly having an actuator on the outside of a compressor body. 1 is a schematic illustration of a reciprocating compressor according to an illustrative embodiment. 1 is a schematic illustration of a valve assembly configured to carry hydrostatic pressure in accordance with an illustrative embodiment. 1 is a schematic illustration of a valve assembly according to an illustrative embodiment. 3 is a schematic view of a valve assembly according to yet another illustrative embodiment. 3 is a schematic view of a valve assembly according to yet another illustrative embodiment. 3 is a schematic view of a valve assembly according to yet another illustrative embodiment. 3 is a schematic view of a valve assembly according to yet another illustrative embodiment. 2 is a flow diagram of a method according to an illustrative embodiment for operating a valve inside a reciprocating compressor used in the oil and gas industry. 2 is a flow diagram illustrating a method according to an exemplary embodiment for retrofitting a reciprocating compressor used in the oil and gas industry.

  In the following description of exemplary embodiments, reference is made to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Rather, the scope of the present invention is defined by the appended claims. The following description of the embodiment relates to the terminology and structure of a reciprocating compressor having an actuator valve used in the oil and gas industry for the sake of simplicity. However, the embodiments described below are not limited to these systems, and can be applied to other systems.

  Throughout this specification the expression “one embodiment” or “an embodiment” includes a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the disclosed invention. Means that Thus, the phrases “in one embodiment” or “in an embodiment” appearing in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, these particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

  One object of the embodiments described below is to provide an apparatus (ie, a valve assembly) and method that allows the use of one or more actuator type valves in a reciprocating compressor. First, it must be considered whether the actuator is located inside or outside the compressor body.

  In the first configuration shown in FIG. 2, the valve assembly 200 is an actuator inside the compressor body 220, in particular inside a cover 230 that is in fluid communication with the compressor body 220 and configured to receive the actuator 210. 210. The stem 240 transmits the displacement and the accompanying operating force to the valve closing member 250 (for example, a disk, a ball, a plug, etc.).

  As an alternative method, the valve assembly 300 includes an actuator 310 disposed outside the compressor body 320, as shown in FIG. For example, the stem 330 penetrates the cover 340 and enters the inside of the compressor main body to operate the valve closing member 350.

  Actuators 210 and 310 may be linear actuators that provide linear displacement or rotary actuators that provide angular displacement. In the case of a linear actuator, the magnitude of the operating force transmitted from the actuator to the movable part of the valve via the actuator shaft varies depending on whether the actuator is disposed inside or outside the compressor body.

In actuator 310 (ie, a linear actuator located outside the compressor body), the actuation force is the first force F ₁ required to overcome the pressure differential across the valve and the fluid inside the compressor body. And the sum of the second force F ₂ required to overcome the hydrostatic pressure, which is the difference between the ambient pressure outside the compressor body and the compressor body. The first force F ₁ is proportional to the surface of the movable part 350 of the valve, and the second force F ₂ is proportional to the surface of the actuator shaft 330. The surface of the actuator shaft 330 is substantially smaller than the surface of the movable part 350 of the valve, but the pressure difference across the valve is substantially less than the hydrostatic pressure (eg 1 bar vs. 300 bar). This actuation force is greater than the force that currently available actuators can provide to achieve a relatively large displacement (eg, about 10-15 mm) in the required short actuation time (eg, about 5 milliseconds). There is also.

In the actuator 210 (that is, a linear actuator disposed inside the compressor body), the operating force only needs to overcome the first force F ₁ due to the pressure difference between the front and back of the valve, and therefore the operation required for the actuator 310 is required. It becomes smaller than power.

  However, when the actuator is placed inside the compressor body, there are additional technical problems that must be overcome, especially when the fluid to be compressed is corrosive and flammable. The internal parts of the actuator require special coatings and sealings to prevent damage from corrosive fluids, which can make heat dissipation difficult. In particular, if the actuator is an electric actuator, operating the actuator inside the compressor body in such a flammable environment is not safe because there is a danger that an explosion may occur due to sparks related to the actuator. Absent.

  Thus, the one or more valve closing members of the one or more valves are configured and connected (one or more) to avoid the risk of explosion of the fluid being compressed (eg, natural gas). The actuator is preferably mounted on the outside of the compressor body so that the actuator is not in direct contact with corrosive and flammable fluids.

  FIG. 4 is a schematic diagram of a reciprocating compressor 400 having one or more actuator type valves. The compressor 400 is a two-chamber reciprocating compressor. However, a valve assembly according to an embodiment similar to that shown in FIGS. 5-10 can also be used in a single chamber reciprocating compressor. Compression takes place in the cylinder 420. A fluid to be compressed (for example, natural gas) is introduced into the cylinder 420 through the inlet 430 and is discharged through the outlet 440 after compression. The compression is performed by the piston 450 moving back and forth between the head side 426 and the crank side 428 along the cylinder 420. The piston 450 divides the cylinder 420 into two compression chambers 422 and 424 that operate at different stages of the circulation process, and when the volume of the compression chamber 422 reaches a minimum value, the volume of the compression chamber 424 reaches a maximum value and vice versa. It is the same.

Suction valves 432 and 434, when opened, allow fluid to be compressed (ie, having a first pressure P ₁ ) to be introduced from inlet 430 into compression chambers 422 and 424, respectively. When the discharge valves 442 and 444 are opened, the compressed fluid (ie, having the second pressure P ₂ ) can be discharged from the compression chambers 422 and 424 via the outlet 440, respectively. The piston 450 moves by receiving energy from a crankshaft (not shown) via a crosshead (not shown) and a piston rod 480, for example. In FIG. 3, valves 432, 434, 442 and 444 are shown as being located on the side wall of cylinder 420. However, the valves 432 and 442 and 434 and 444 may be disposed on the head side 426 or the crank side 428 of the cylinder 420, respectively.

  In contrast to an automatic valve that opens due to differential pressure across the valve closing member of the valve, an actuator-type valve such as 432 in FIG. 4 has an actuator such as 437 in FIG. When a force transmitted to the closing member 433 is applied to induce a linear displacement or an angular displacement of the valve closing member 433, the opening opens. The stem 435 is not intended to limit the manner in which actuation motion is transmitted from the actuator 437 to the valve closure member, and other motion transmission and conversion mechanisms may be used for this purpose instead of the stem 435. Good. One or more valves of the reciprocating compressor 400 may be actuator type valves. In some embodiments, a combination of an actuator valve and an automatic valve is also conceivable, for example, the suction valve may be an actuator valve while the discharge valve may be an automatic valve.

  One or more actuator type valves (eg, 432 in FIG. 4) include a valve assembly configured to carry hydrostatic pressure, such as the valve assembly 500 shown in FIG. The actuator 510 causes a displacement (linear or angular) and transmits this displacement to the valve closing member 530 via the stem 520. The stem 520 enters the inside of the compressor body 540. Proximal to the entry location and inside the compressor body 540, the stem 520 has a collar 550 (ie, a portion having a larger diameter). The valve assembly 500 further includes a bushing 560 disposed between the collar 550 and the compressor body 540. One or more motion seals 570 (eg, labyrinth seals) disposed between the compressor body 540 and the shaft 520 prevent fluid from escaping from the inside of the compressor body 540 into the environment.

  Using various mechanical elements between the actuator 510 and the position where the stem 520 enters the inside of the compressor body 540 or between the position where the stem 520 enters the inside of the compressor body 540 and the valve closing member 530, Amplification of linear and angular displacements caused by the actuator 540 and / or conversion between these displacements can be performed. At a position where the stem 520 enters the compressor body 540, the stem 520 performs a rotational motion (ie, related to angular displacement). These various elements are not specifically shown in FIG. 5 (indicated by dashed lines), but their embodiments are illustrated and described in connection with FIGS.

  At the position where the shaft 520 enters the compressor body 540, the hydrostatic pressure presses the collar 550 toward the bushing 560 and thus bears the hydrostatic pressure without affecting the rotational motion of the shaft 520.

  FIG. 6 is a schematic diagram of a valve assembly 600 according to an illustrative embodiment. The actuator 610 disposed outside the compressor body 620 is configured to cause the stem 630 that enters the inside of the compressor body 620 to perform angular displacement.

  Stem 630 includes collars 632 and 634 proximate cover shaft supports 640 and 650, respectively. Cover supports 640 and 650 and cover 660 are assembled together to receive and support valve assembly 600. Fixed seals 642 and 652 (eg, O-rings) disposed between cover supports 640 and 650 and cover 660, respectively, ensure that high pressure fluid inside the compressor body does not leak out of the compressor body. To.

  A thrust bushing 644 disposed between the collar 632 and the cover shaft support 640 is configured to bear a force due to hydrostatic pressure. One or more motion seals 646 (eg, labyrinth seals) positioned between the shaft 630 and the cover 660 ensure that high pressure fluid does not leak out of the compressor.

  Cam 636 is attached to shaft 630 between collars 632 and 634. To facilitate installation, at least one of the collars 632 and 634 may be removable from the shaft 630, but the collars 632 and 634 are fixedly attached during operation (eg, one collar is integral with the shaft 630). May be formed). The cam 636 has an asymmetric shape with respect to the rotation axis of the shaft 630. The cam 636 is configured to contact a stem 670 that is connected to a valve closing member 680 of a linear valve (eg, a popper valve or ring valve). Due to the shape of the cam 636, the rotational displacement transmitted from the actuator 610 to the shaft 630 is converted into a linear displacement of the valve closing member 680.

  Thus, in the assembly 600, the shaft 630 bears the angular displacement caused by the actuator 610 disposed outside the compressor body. Collar 632 and thrust bushing 644 are configured to carry hydrostatic pressure so that hydrostatic pressure does not affect the transmission of this displacement.

  FIG. 7 is a schematic diagram of a valve assembly 700 in accordance with yet another illustrative embodiment. Some components of the valve assembly 700 are similar to those of the valve assembly 600 of FIG. 6 and are therefore numbered the same and will not be described again to avoid repetition. However, similar components may have substantially different characteristics. The actuator 610 disposed outside the compressor body 620 is configured to cause the shaft 730 entering the inside of the compressor body 620 to perform angular displacement. Shaft 730 has collars 732 and 734 proximate cover shaft supports 640 and 650. Cover supports 640 and 650 and cover 660 are assembled together to receive and support valve assembly 700.

  Axis 730 includes a portion 736 that is substantially parallel to its axis of rotation but at a predetermined significant distance from the axis of rotation (ie, significant enough to affect the movement of an element attached to that portion). Configured to have. A connecting rod 770 is attached to portion 736. The end 772 on the portion 736 side of the connecting rod 770 rotates with the portion 736 while the opposite end 774 connected to the stem 775 undergoes a linear displacement. This linear displacement is transmitted via the stem 775 to the valve closing member 680 of the valve.

  Thus, in the assembly 700, the shaft 730 bears an angular displacement by the actuator 610 disposed outside the compressor body 620. The collar 632 and the thrust bushing 644 are configured to carry hydrostatic pressure so as not to affect the transmission of this angular displacement.

  FIG. 8 is a schematic illustration of a valve assembly 800 in accordance with yet another illustrative embodiment. In valve assembly 800, linear displacement caused by actuator 810 is converted to angular displacement (ie, rotational motion) by linear-rotation converter 820. The design of the linear-rotation transducer (ie, the relative dimensions of the components) is such that the displacement caused by the actuator 810 is amplified. Both the actuator 810 and the linear-rotation converter 820 are disposed outside the compressor body 830. In FIG. 8, the actuator 810 is shown separated from the linear-rotation transducer 820. However, in yet another embodiment, the actuator 810 and the elements of the linear-rotation transducer 820 can be mounted inside the same housing.

  The linear displacement caused by the actuator 810 is transmitted to the rotating shaft 860 side of the connecting rod 850 via the actuator shaft 840. Connecting rod 850 has one end 852 attached to actuator shaft 840 and an opposite end 854 attached to portion 862 of shaft 860. Axis 860 is configured to rotate about an axis that is substantially parallel but at a significant distance from portion 862. Depending on the shape of the shaft 860 and the manner in which the connecting rod 850 moves, linear displacement is converted into angular displacement (ie, rotational motion) of the shaft 860. Inside the linear-rotation transducer 820, the shaft 860 is supported by a bearing 870.

  The shaft 860 is configured to enter the inside of the compressor main body 830, and the end of the shaft 860 is connected to the movable portion 890 of the rotary valve inside the compressor main body. The shaft 860 has a collar 864. A thrust bearing 880 disposed between the collar 864 and the cover 832 of the compressor body 830 attenuates the force due to hydrostatic pressure. A motion seal 882 disposed between the cover 832 and the shaft 860 prevents fluid inside the compressor body 830 from leaking out of the compressor body.

  Thus, in the assembly 800, the shaft 860 transmits angular displacement to the inside of the compressor body 830, while the collar 832 and the thrust bushing 844 are configured to bear hydrostatic pressure. Do not affect the transmission of displacement.

  FIG. 9 is a schematic diagram of a valve assembly 900 in accordance with another illustrative embodiment. An actuator 910 disposed outside the compressor body 920 causes the shaft 930 to perform angular displacement (ie, rotational movement). The shaft 930 passes through the cover 940 and enters the inside of the compressor body 920. The shaft 930 has a collar 932 that is pressed by hydrostatic pressure toward a thrust bearing 950 disposed between the collar 932 and the cover 940. Thrust bearing 950 attenuates the force due to hydrostatic pressure. A motion seal 952 disposed between the cover 940 and the shaft 930 prevents fluid inside the compressor body 920 from leaking out of the compressor body.

  Inside the compressor body 920, the angular displacement of the shaft 930 is converted into a linear displacement by the screw jack mechanism 960. The screw jack mechanism 960 is fixedly attached to a screw jack cover 970 disposed between the cover 940 and the cylinder body 920. The screw jack mechanism 960 has a female thread and the shaft 930 has a male thread, so that angular displacement is converted to linear displacement. For example, the screw jack mechanism 960 pushes an actuator shaft 980 attached to a valve closing member 990 of a linear valve (for example, a poppet valve or a ring valve) in a linear motion.

  Thus, in the assembly 900, the shaft 930 transmits the angular displacement caused by the actuator 910 arranged outside the compressor body. The collar 932 and the thrust bushing 950 are configured to carry a hydrostatic pressure so that the hydrostatic pressure does not affect the transmission of this displacement.

  FIG. 10 is a schematic illustration of a valve assembly 1000 according to yet another illustrative embodiment. An actuator 1010 disposed outside the compressor body 1020 causes the shaft 1030 to perform angular displacement. The shaft 1030 penetrates the cover 1040 and enters the inside of the compressor body. The shaft 1030 has a collar 1032 having a diameter that is greater than the shaft diameter along most of its length. A thrust bearing 1050 disposed between the collar 1032 and the cover 1040 attenuates the force due to hydrostatic pressure. A motion seal 1052 disposed between the cover 1040 and the shaft 1030 prevents fluid inside the compressor body 1020 from leaking out of the compressor body.

  Further, the valve assembly 1000 includes an actuator shaft 1060 to which a rotary valve closing member 1070 is attached to a first end 1062 of the actuator shaft. The rotary valve also includes a fixed valve seat (stator) 1080. In the first position, the valve opens when the opening 1082 passing through the valve seat 1080 overlaps the opening 1072 passing through the rotary valve 1070. By rotating the valve closing member 1070 of the rotary valve relative to the valve seat 1080 to the second position, the openings 1072 and 1082 no longer overlap and the valve is closed.

  Thus, the shaft 1030 bears angular displacement by the actuator 1010 disposed outside the compressor body. The collar 1032 and the thrust bushing 1044 are configured to carry a hydrostatic pressure so that the hydrostatic pressure does not affect the transmission of this angular displacement.

  In summary, FIGS. 5-10 show a valve assembly that can be used in a reciprocating compressor for the oil and gas industry. These valve assemblies include an actuator disposed on the outside of the compressor body, which is connected to a shaft that transmits angular displacement (rotational motion) that enters the interior of the compressor body. Inside the compressor body, close to the position where the shaft enters the inside of the compressor body, the thrust bush and the collar of the shaft are hydrostatic (the fluid inside the compressor body and the environment outside the compressor body To reduce the hydrostatic pressure from affecting the transmission of rotational movement (ie angular displacement). In this way, the hydrostatic pressure does not affect the actuator. Furthermore, since the actuator is outside the compressor body, no special coating and sealing is required.

  A flow diagram of a method 1100 according to an illustrative embodiment for operating a valve inside a reciprocating compressor used in the oil and gas industry is shown in FIG. The method 1100 includes a step S1110 of causing displacement and a compressor body with a second fluid medium having a substantially higher pressure than the first fluid medium from outside the compressor body with the first fluid medium. And a step S1120 of transmitting a rotational motion due to the displacement through the shaft inside. In addition, the method 1100 uses a collar on the inner shaft of the compressor body and a thrust bush between the collar and the compressor body to provide a space between the second medium and the first medium. Step S1130 for attenuating force due to hydrostatic pressure is included.

  The method 1100 may also include dynamically sealing the interface between the shaft and the compressor body at a location where the shaft enters the interior of the compressor body. If the displacement is an angular displacement that causes rotational motion and the valve is a linear valve, then the method 1100 further converts the angular displacement to a linear displacement to actuate the valve closing member of the linear valve inside the compressor body. A step of allowing. If the displacement is a linear displacement, the method 1100 may further include converting the linear displacement into rotational motion outside the compressor body.

  The method 1100 may include (1) amplifying the displacement between the actuator and the shaft outside the compressor body and / or (2) rotating motion between the shaft and the valve closing member of the valve inside the compressor body. May be included.

  The reciprocating compressor with automatic valve used in the oil and gas industry can be retrofitted to be an actuator-type valve having a valve assembly in which one or more valves are configured to bear the hydrostatic pressure. A flow diagram of a method 1200 for retrofitting a reciprocating compressor having an automatic valve that operates based on the differential pressure across the valve closing member of the valve is shown in FIG. The method 1200 includes installing an actuator S1210 that is configured to cause displacement outside the compressor body of the reciprocating compressor. Further, the method 1200 includes a step S1220 of connecting a shaft penetrating the inside of the compressor body to the valve closing member of the automatic valve, the shaft being configured to receive a rotational motion related to the displacement, It has a collar close to the position where the shaft enters the inside of the compressor body. Finally, the method 1200 dampens the hydrostatic pressure forces between the collar and the compressor body inside the compressor body and the fluid inside the compressor body and the environment outside the compressor body. A step S1230 of attaching a thrust bushing configured as described above.

  The method 1200 may also include attaching one or more motion seals to the interface between the shaft and the compressor body at a location where the shaft enters the interior of the compressor body. If the displacement is an angular displacement and the valve is a linear valve, the method 1200 is further configured to convert the angular displacement that causes the rotational motion into a linear displacement to actuate the valve closing member of the linear valve. A step of attaching the mechanism to the inside of the compressor body may be included. If the actuator causes a linear displacement, the method 1200 further includes the step of attaching a linear-rotational transducer configured to convert the linear displacement into rotational motion between the actuator and the shaft outside the compressor body. May include.

  To facilitate actuation of the valve, the method 1200 includes (1) installing a displacement amplification mechanism configured to amplify the displacement between the actuator and the shaft and / or (2) amplifying the rotational motion. A displacement amplifying mechanism configured between the shaft and the valve closing member of the valve may be included.

  The illustrative embodiments of the disclosure are configured such that hydrostatic pressure does not affect the transmission of displacement from an actuator disposed outside the compressor body to a valve closing member of a valve inside the compressor body. A valve assembly is provided. It should be understood that this description is not intended to limit the invention. Rather, the exemplary embodiments are intended to cover alternatives, modifications, and equivalents that fall within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the detailed description of the illustrative embodiments, numerous specific details are set forth in order to provide a thorough understanding of the present invention as set forth in the claims. However, one of ordinary skill in the art appreciates that various embodiments can be practiced without such specific details.

  In the illustrative embodiments of the invention, the features and elements of the embodiments have been described in specific combinations, but each feature or element can be used alone or without the other features and elements of the embodiment. It can be used in various combinations or uncombinations with other features and elements disclosed in the document.

  This written description uses examples of the disclosed invention to enable any person skilled in the art to practice the invention, including the fabrication and use of any apparatus or system and the execution of any method incorporated herein. It is what makes it possible. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be included within the scope of the claims.

Claims (7)

For valve assemblies that can be used in reciprocating compressors for the oil and gas industry,
An actuator configured to cause displacement;
A shaft configured to receive a rotational motion caused by the displacement and to enter the inside of the body of the reciprocating compressor;
A collar disposed close to a position where the shaft enters the inside of the compressor body;
A thrust bushing disposed between the collar and the compressor body;
The displacement is an angular displacement, the valve is a linear valve, and is disposed inside the compressor body and converts the angular displacement that causes the rotational motion into a linear displacement to operate a valve closing member of the linear valve A displacement transmission mechanism configured to cause
Including, valve assembly.   The valve assembly of claim 1, further comprising one or more motion seals disposed at an interface between the shaft and the compressor body at a location where the shaft enters the interior of the compressor body. . In a method of operating a valve inside a reciprocating compressor used in the oil and gas industry,
A stage of causing displacement;
The rotational movement due to the displacement is effected via an axis from the outside of the compressor body with the first fluid medium to the inside of the compressor body with the second fluid medium having a pressure substantially higher than that of the first medium. The stage of communicating
By using a collar on the shaft inside the compressor body and a thrust bush between the collar and the compressor body, between the first fluid medium and the second fluid medium. Removing the force due to hydrostatic pressure;
The displacement is an angular displacement, the valve is a linear valve, and inside the compressor body, the angular displacement that causes the rotational motion is converted into a linear displacement to actuate a valve closing member of the linear valve. When,
Including the method. In reciprocating compressors used in the oil and gas industry,
A compressor body configured to separate fluid from the environment;
At least one valve assembly configured to operate a valve on the compressor body comprising:
An actuator disposed outside the compressor body and configured to cause displacement;
A shaft configured to receive a rotational motion caused by said displacement and to enter inside a compressor body of a reciprocating compressor;
A collar disposed close to a position where the shaft enters the inside of the compressor body;
A thrust bushing disposed between the collar and the compressor body inside the compressor body and configured to reduce hydrostatic pressure between the fluid and the environment;
The displacement is an angular displacement, the valve is a linear valve, and is disposed inside the compressor body and converts the angular displacement that causes the rotational motion into a linear displacement to convert the valve closing member of the linear valve. A displacement transmission mechanism configured to be actuated;
A valve assembly comprising:
A reciprocating compressor. The reciprocating compressor of claim 4 , further comprising one or more motion seals disposed between the shaft and the compressor body at the position where the shaft enters the interior of the compressor body. (1) arranged between the actuator and the shaft to amplify the displacement, or (2) arranged between the shaft and the valve closing member of the valve and The reciprocating compressor of claim 4 or 5 , further comprising a displacement amplifying mechanism configured to amplify the rotational motion. In the method of refurbishing a reciprocating compressor having an automatic valve initially,
Attaching an actuator configured to cause displacement outside a compressor body of the reciprocating compressor;
An axis that enters the inside of the compressor body, and is configured to receive a rotational motion due to the displacement, and has an axis that has a collar adjacent to a position where it enters the inside of the compressor body. Connecting to a valve closing member of the automatic valve;
A thrust bush configured to reduce a hydrostatic pressure force between a fluid inside the compressor body and an environment outside the compressor body includes the collar and the compressor body inside the compressor body. And the stage of mounting between
The displacement is an angular displacement, the automatic valve is a linear valve, and the angular displacement that causes the rotational motion is converted into a linear displacement inside the compressor body to operate a valve closing member of the linear valve. Stages,
Including.